[substack]

It's similar how with a torrent you can start seeking into a particular spot in a file and start playing by requesting particular chunks at that spot. Some clients like webtorrent support this behavior but it changes the dynamics of the network somewhat if many clients do this kind of thing. You can build some supplementary peer info to help the process along for different p2p networks depending on if they let you create side-channels or let you make more explicit connections to peers. For peermaps, the database is file and directory based so most of that peer tree traversal should be handled already by the network. And there are more ways to optimize the connections with additional tricks once you get the basics working with a somewhat slower and less sophisticated transfer method.